Airliners are not instrumented like a laboratory gig. The gauges and procedures are indicative regarding the type of problem and more troubleshooting is expected to close on a faulty system. A technical investigation can´t stop at staring at the instrument panel. You know that. Mechanics do have often to trace back the faulty system and pilot´s indications are key to that.
Yes, they are. And there has been nothing reported that would point a mechanic troubleshooting the pressurization system
towards the plugs. I would more likely suspect the electrical connections at the Pressurization Controller before a crack or leaking door.
Look. The pressurization system on the older planes is pretty dumb. You tell it to maintain X pressure differential, it vents air out to hold the pressure there. It doesn't say, "Hey, wait, I'm needing a lot less outflow door that I should be using at this engine RPM, something isn't right." It's not like say, the Mass Airflow Sensor and ECU on a 2000s Chrysler Hemi, that says "I'm seeing a lot more air than I should be for how much throttle there is, something is wrong" and throws the engine into limp-home mode when Joe hotrodder hooked up a supercharger to his Hemi for Moah Powah!!!!
It might be possible to have such a system installed without modifying the airframe, as long as the motors that control the outflow valve are steppers and know where they are in their travel. Then you could simply reprogram the Pressurization Controller with a map comparing outflow position with commanded differential pressure versus engine RPM (and therefore how much bleed air you're packing into the tube).
When those passengers reported thd problem, a significant piece of evidence was disregarded that should have been taken into consideration.
Where were these passengers seated and can they describe to the cabin crew where they heard the sound? Can the cabin crew relay that information to the mechanics?
That it would be by pedantism, inattention, fatigue, miscommunication, that very fact is there as surely as an uncompleted plane being put into service by Boeing.
IMOHO, the NTSB should have that covered in their investigation as well. It makes no sense otherwise.
Have we seen a Final Report from the NTSB?
If not, how do you know that the NTSB isn't covering that?
The plug blowing out at such a low alt would also indicate that an appropriate pre-flight inspection could have detected a faulty panel adjustment.
Do me a favor.
Go try to see where the plug physically is on the aircraft, while you're standing on the ground 20 feet below it.
Now try to see if the plug is standing proud of the surface at any point. I'm willing to bet that the design actually has the skin of the plug sitting on top of the fuselage skin. That will make it stand 1-2mm proud of the skin around it, without a gap. It would also make it impossible to see light through any gap due to the shape of the fuselage.
The faulty pressurization indicator in the climbing portion of the flight (at such a low alt, just above cabin pressure activation) could have seen another crew electing to turn back or circle the time the cabin crew made an inspection...
All this are signs that the craziness certainly didn´t stop at Spirit or Boeing.
You are pointing at that cabin pressurization fault as if it's some smoking gun. IT IS NOT A SMOKING GUN. All it says is that the Controller cannot maintain ordered pressure differential. It could be that the primary controller itself is failing. There could be an electrical fault somewhere.
In no way does it suggest that the cabin doors, baggage doors, or the door plugs might not be sealing properly.
The plane was literally on it's way to the Alaska Airlines maintenance depot at the end of this flight. What the hell more do you want to do?
